Alternative fuel vehicles, such as hybrid and fuel cell vehicles, include electric motors and other components that often use alternating current (AC) power supplies. However, the power supplies, such as batteries and fuel cells, used in such applications may only provide direct current (DC) power. Thus, a power inverter may be used to convert the DC power to AC power.
Modern automotive power inverters often utilize power module assemblies that include integrated circuits with multiple semiconductor devices (e.g., transistors and diodes) formed thereon to convert the DC power to AC power. Due to the high levels of current, the power modules may generate large amounts of heat. In order to ensure reliable performance, the power module assemblies typically have cooling systems to transfer heat out of the inverter assembly.
Conventional cooling systems used in automotive inverter assemblies often include a baseplate functioning as a heat sink mounted on the manifold of the power module assembly. Heat from the power modules is conducted through the power modules to the baseplates, where it is removed from the power module assembly by a coolant.
Simple heat sink cooling systems of the type described above may not achieve optimal power device cooling. For example, heat dissipation may be reduced by coolant stagnation. These limitations may be mitigated by employing an active cooling system, which utilizes a pump to circulate the coolant fluid over or onto the power device. However, even active cooling systems are also limited in certain respects. Such cooling systems tend to be relatively complex and expensive to employ.
Accordingly, it is desirable to have automotive power module assemblies that are compact in size, have fewer parts than conventional systems, provide improved cooling of the high power devices, and are of lower cost than conventional systems. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.